use Perl

• Of course, the right way to write that... (Score:1)

  by Aristotle (5147) <pagaltzis@gmx.de> on 2008.06.25 10:46 (#63615) Homepage Journal

  … is like this:

  sub fact ( Int $n ) { [*] 1 .. $n }

  ;-)

  (I’ve no idea if that actually works in the current state of Rakudo.)

  Reply to This

  • Re: (Score:2)

    by Ovid (2709)

    No, the right way to write that is:

    subset PosInt of Int where { $_ > 0 }
    sub fact ( PosInt $n ) { [*] 1 .. $n }

    :)
    • Re:Of course, the right way to write that… (Score:1)

      by Aristotle (5147)

      :-)

      (Actually, that should be >= – factorial is defined for zero. :-))
      • Re: (Score:1)

        by Aristotle (5147)

        Hmm, except 1 .. 0 won’t work right, so then it needs to be [*] 1 .. min( 1, $n ), which is a little uglier, though manageable.
        • Re: (Score:1)

          by polettix (7564)

          Maybe you meant max instead of min?
          • Re: (Score:1)

            by Aristotle (5147)

            Err, yes.